Hydraulic jack



Feb. 24, 1931.

H. W. BOLENS HYDRAULIC JACK Filed Oct.

A TTORNE Y.

Patented Feb. 1931 nanny w. rornns' or fronr w'AsHmG'ron, wrsconsm Hsznn'aumo JACK -Ap plication fild October 31, 192k. 'ser 1-m. m,89a

This invention relates toan improvement. inihydraulio jacks of} the type. espec ally lei:

having'this capacity and also'coacting with the piston of the hydraulic jack .in; such a novel and efiective manner that the lifting mechanism and the piston, and cylinder assembly mutually coact to guide and-strengthen eachother. l

, Another object of the inventionistopro .vide 'a hydraulic jack construction having cessive pressures below the pistonafter the piston hasbeen elevatedras far'as it may be in the cylinder, this means: serving this func tion without being liable to injure orv score thepiston. J I p Another object is to provide lifting mechanism-of a hydraulic jack oftthe type having, a

lifting lug and wherein the liftingflugs is.

freely adjustable along its carrier and yet-is prevented from falling ofi. of the same even in its lowermost adjustments.

Other objects and advantages reside in certain novel features of the constructiomarrangement and combination of parts which will be hereinafter more fully described and claims, reference being had to the accompanying drawings, forming a part of this specifica tion, and in which: v

Figure l is a view partly in side elevation and partly in section taken on line 11 of Referring to the drawings, numeral '1 jack eifective and conveniently usable gover a wide range of heights, the hfting mechanism ,formno part of this invention and are well ,ln own, For the purposespf :the present 1nvent1on it is suflioient' to understand that means for preventing the application of exparticularly pointed out in the appended Figure 4, showing a hydraulic jack embodydesignates the base -of -the hydraulic ljack. Integral with the base is ai cylinder -2 in which, a piston 3 isjfitted. The piston irhas apisto'n rod 4; secured thereto and extending v upwardly therefromythepiston rod .4: being a working fit through the usual stufiing'box (not shown) provided atthe upper end of the cylinder 2. l-A handoperatedpump 5.

is provioled andis swiveled to the-base 1 and connected: by valve controlled passages to the opposlte ends of the cylinder 2, that is, above and below the piston; The details of the con struct on ofthe pump v5 and of the valve con trolled means; between it and the cylinder 2 the pump 5 maybe-utilized to withdraw the oil or other fluid fromfthetopzof the cylinder 2 above the piston 3 through a port 6 and return vpassages-7 and to force this'fiuid.

.into "the lower end ofthe cylinder below the piston through the, passage 8. I c- With an arrangement'of this character. if the pump is operated, after thepiston 3 has been elevated as far as [it may be, excessive and evenldestr'uctive pressuresmay' be. set 7 1113 111 the cylinders and to avoid this a minute by pass port 10 is provided between the cylinder and the return passage 7 at apoint just below the piston 3 when-the piston is in its 7 extreme upper position. Such-a venting port 10 provides for the relief of anyexcessivc pressures and, does so without interfering with the maintenance of the piston 3 in its $5 uppermost position and without liability of scoring or damaging the piston. Usually these pistons have leather cups or washers which would be clamagedifexpanded into an opening of. anysize. V'The reliefport 10' cylinder 2 in parallel relation to the piston by means of curved guiding Wings integral 15 vided in the bar16 (see Figure 5). With this e n he pist n 3 ri 't n r d-A are constrained to true sliding-"movement by virtue of the coaction of the guide bar..16. and...

the rib 17 and theflpi ton and pistoarndhaaing a similar actionon 'the ame-tar! The guiding action of the guide bar is enhancedwith the lower end of; the bar; and; sliding against the outer surface of the cylinder. 1

The bar 16 has-twovertical rowso-fiteeth 24 spaced-by anfintervening i'ib' 24 A lifting lug- 21 is adjustablyniounte'd on the bar 1'6an'd includes abody portion :22 adapt'ed" to engage the objectj'toj beraised, a down' wardly and inwardly curved 'lugj 23. notched to clear the rib and to 'perinitlits lower end portions to engage the spaced teeth 'Qe on' the bar 16",and hook-like retaining fingers25' which extendaround; and engag'e'the bar as i this portion 15 is less than the distancebethis operation will-eifect assembly ofthellug, I r v I t i riband hayingtwo'rows of teeth with an inshown inFigure 5. The 'ba r f16 i's cut away at 16 to provide to receiye thehoolrs 25, these ways terminatingshort of the lower end of thebar to provide stops 27 which lim t the downward movement of the liftinglug; p ernt tsb ne a ped f i 1 116 ar} and 16. a v o p r To takethe lifting lug21 off of theba r 16;; it israised up along thelbar 16 agar as it will go andis then rotated until'the body por i tion 22, is in a substantially vertical plane with the hooks 25 aline'djwiththe portionfl5f 1 between the head 15 and'the bar'lfi; 'At least one (preferably the, vertical) dimenSiO lI of tween the hooks so thatby keepingthelugfll in a substantially vertical'planefand rotating it in either direction, itmay be slipped later f ally off of the portion 15"; The reverse of- 21 and the lift bar16. V

The'head15is roughened so as to beadapte ed to engageproperly an objector apart of the vehicle. In order toia dapt the jack for; engaging objectsspa ced abovethe ground beyond the rangeofthe head;1 5., an auxiliary lifting headfiO is, provided andhas an offset hinged connection 31with the headu15.

This auxiliary head 30 may beoperatively positioned as shown in full lines inFigurel in which position it is engagediwith'andfirmly supported by the head 15" andis ready for use. Again, the auXiliary head'SO inay be swung. a; ai s id' apa te "d ies,- lines i Figure 11111 which p si i dftheheadi 3o ieither the head 15 0i; the; lifting hi ffa' must beused.

efi fil -j e rieeeleimey be p a 'i e g between the head 15 and the base 1 to aid in the lowering of the jack. r r

' From the foregoing it will be seen that the lifting mechanism has a'wide range of action and yet is especially adapted for organization with a hydraulic jack. Thus, the lifting head, lifting bar and cylinder are interconnectedto guide and strengthen eachjlother and afford adequate strength and-- rigidity in the'support of the lifting head and of the lifting lugbflThe auxiliary'lifting headin creases "tlie'rarige of actionof the jack and when inuse is firmly supported. Finally the cylinder of the jack is relieved of excessive pressures in sucha novel manner as to avoid eration the portions of the drill holes'that lie between the exterior and the jreturn passage 7-' are' pluggedup; as indicated at and rier fo'rthe lifting'lugysaid "carrier having two rows of'teeth withanfintervening rib thereon and said lifting l-ug'having a' depending portion notched to interfit with the rib on said carrier andto permit its lower end to engagethe spaced teeth on said carrier.

f jack including; a' lifting lug and a carrier therefonsaidcarrier having two rows of teeth; with an intervening iib'on' oneface' thereoffand guide ways on an opposite face of'the carrier, saidguide ways terminatin short of end of the carrier and sai lifting lug having 'a depending portion notched'to .interfit with s aidrib and'to per llllilflts lower 'en'clto engage said spaced teeth,

said lifting luggalso having. hooks thereonfor" ngagi a i i -e de W y I 3; A; jack incliiding" a cylinder, a guiding rib on "said cylinder, a lifting lug carrierhaw' ing a guide Wayp Operating withfsaid guide WJBQLENSQ 

